Posted: Mon Feb 06, 2017 12:30 am
This puzzle isn't difficult, but if you are having trouble, here are two solutions, depending on your starting configuration.
I use numbering as
1 2 3
4 5 6
7 8 9
Start is all BLUE
I use numbering as
1 2 3
4 5 6
7 8 9
Start is all BLUE
Start is all blue except center #5 is RED
There are shorter sequences, and of course the puzzle is symmetrical, so there are lots of similar solutions.